P
US8147209B2ExpiredUtilityPatentIndex 82

Wind turbine blade

Assignee: GODSK KRISTIAN BALSCHMIDTPriority: Feb 22, 2005Filed: Feb 22, 2005Granted: Apr 3, 2012
Est. expiryFeb 22, 2025(expired)· nominal 20-yr term from priority
Inventors:GODSK KRISTIAN BALSCHMIDTNIELSEN THOMAS S BJERTRUP
F05C 2253/16F03D 7/024F03D 7/0224F05B 2270/322Y10S416/02F05B 2270/1016F03D 7/0296F03D 1/0641F05B 2280/6013F05C 2253/22F05B 2280/702Y02E10/72
82
PatentIndex Score
8
Cited by
12
References
29
Claims

Abstract

A wind turbine comprising a wind turbine blade with high lift and/or low solidity is provided. The blade is directed towards pitch regulated wind turbines, which are operated at variable rotor speed and have blades longer than about 30 meters. The blade is for example advantageous in that it may provide reduced extreme and fatigue loads at the same or near the same power production.

Claims

exact text as granted — not AI-modified
The invention claimed is: 
     
       1. A wind turbine operable by pitch regulation and variable rotor speed, comprising at least one wind turbine blade longer than 30 meters, where a combined radius specific solidity Sol r  is below a linear interpolation between:
 Sol r =0.035 at blade radius r=30% of the rotor radius R 
 Sol r =0.025 at blade radius r=50% of the rotor radius R 
 Sol r =0.018 at blade radius r=70% of the rotor radius R 
 Sol r =0.011 at blade radius r=90% of the rotor radius R, 
 for at least 50 radius-% of the blade(s) between blade radius r=30-90% of the rotor radius R, 
 where the maximum lift coefficient C L,max >1.45 for a Reynolds number Re=1.5×10 6 . 
 
     
     
       2. The wind turbine according to  claim 1 , where the combined radius specific solidity is below a linear interpolation between:
 Sol r =0.034 at blade radius r=30% of the rotor radius R 
 Sol r =0.022 at blade radius r=50% of the rotor radius R 
 Sol r =0.016 at blade radius r=70% of the rotor radius R 
 Sol r =0.010 at blade radius r=90% of the rotor radius R, 
 for at least 50 radius-% of the blade(s) between blade radius r=30-90% of the rotor radius R. 
 
     
     
       3. The wind turbine according to  claim 2 , where the combined radius specific solidity is below a linear interpolation between:
 Sol r =0.034 at blade radius r=30% of the rotor radius R 
 Sol r =0.022 at blade radius r=50% of the rotor radius R 
 Sol r =0.016 at blade radius r=70% of the rotor radius R 
 Sol r =0.010 at blade radius r=90% of the rotor radius R, 
 for at least 75 radius-% of the blade(s) between blade radius r=30-90% of the rotor radius R. 
 
     
     
       4. The wind turbine according to  claim 2 , where the combined radius specific solidity is below a linear interpolation between:
 Sol r =0.034 at blade radius r=30% of the rotor radius R 
 Sol r =0.022 at blade radius r=50% of the rotor radius R 
 Sol r =0.016 at blade radius r=70% of the rotor radius R 
 Sol r =0.010 at blade radius r=90% of the rotor radius R, 
 for at least 95 radius-% of the blade(s) between blade radius r=30-90% of the rotor radius R. 
 
     
     
       5. The wind turbine according to  claim 1 , wherein
 the maximum lift coefficient C L,max >1.5, for Re=1.5×10 6 , and/or 
 the maximum lift coefficient C L,max >1.58, for Re=3.0×10 6 , and/or 
 the maximum lift coefficient C L,max >1.64, for Re=5.0×10 6  and/or 
 the maximum lift coefficient C L,max >1.68, for Re=7.0×10 6 , and/or 
 the maximum lift coefficient C L,max >1.71, for Re=9.0×10 6 , and/or 
 the maximum lift coefficient C L,max >1.73, for Re=11.0×10 6    
 where C L,max  is valid for a two-dimensional flow passing a smooth profile surface for at least 80 radius-% of the blade. 
 
     
     
       6. The wind turbine according to  claim 5 , wherein C L,max  is valid for a two-dimensional flow passing a smooth profile surface for at least 90 radius-% of the blade. 
     
     
       7. The wind turbine according to  claim 1 , wherein
 the maximum lift coefficient, C L,max >1.45 for Re=1.5×10 6 , and/or 
 the maximum lift coefficient, C L,max >1.5 for Re=3.0×10 6 , andor 
 the maximum lift coefficient, C L,max >1.6 for Re=5.0×10 6 , and/or, 
 the maximum lift coefficient, C L,max >1.65 for Re=7.0×10 6 , and/or 
 the maximum lift coefficient, C L,max >1.68 for Re=9.0×10 6 , and/or 
 the maximum lift coefficient, C L,max >1.7 for Re=11.0×10 6    
 where C L,max  is valid for a two-dimensional flow passing a smooth profile surface, for profiles in the radius range corresponding to t/c<27% to t/c>15% with the proviso that r<96% of R. 
 
     
     
       8. The wind turbine according to  claim 7 , wherein C L,max  is valid for a two-dimensional flow passing a smooth profile surface, for profiles in the radius range corresponding to t/c<24% to t/c>15% with the proviso that r<96% of R. 
     
     
       9. The wind turbine according to  claim 1 , wherein
 the maximum lift coefficient C L,max >1.5, for Re=1.5×10 6 , and/or 
 the maximum lift coefficient C L,max >1.58, for Re=3.0×10 6 , and/or 
 the maximum lift coefficient C L,max >1.64, for Re=5.0×10 6 , and/or 
 the maximum lift coefficient C L,max >1.68, for Re=7.0×10 6 , and/or 
 the maximum lift coefficient C L,max >1.71, for Re=9.0×10 6 , and/or 
 the maximum lift coefficient C L,max >1.73, for Re=11.0×10 6    
 where C L,max  is valid for a two-dimensional flow passing a smooth profile surface, for profiles in the radius range corresponding to t/c<27% to t/c>15% with the proviso that r<96% of R. 
 
     
     
       10. The wind turbine according to  claim 9 , wherein C L,max  is valid for a two-dimensional flow passing a smooth profile surface, for profiles in the radius range corresponding to t/c<24% to t/c>15% with the proviso that r<96% of R. 
     
     
       11. The wind turbine according to  claim 1 , wherein the combined radius specific solidity decreases substantially linearly between blade radius r=40% of R to r=90% of R. 
     
     
       12. The wind turbine according to  claim 11 , wherein the combined radius specific solidity decreases substantially linearly between blade radius r=50% of R to r=90% of R. 
     
     
       13. The wind turbine according to  claim 11 , wherein the combined radius specific solidity decreases substantially linearly between blade radius r=60% of R to r=80% of R. 
     
     
       14. The wind turbine according to  claim 1 , operable by pitch regulation and variable rotor speed, having at least one wind turbine blade longer than 30 meters, wherein the C L,d >1.3 for Re=3.0-11×10 6  corresponding to two-dimensional flow passing a smooth profile surface and for t/c<24%, with the proviso that r>96% of R. 
     
     
       15. The wind turbine according to  claim 14 , wherein the C L,d >1.3 for Re=3.0-11×10 6  corresponding to two-dimensional flow passing a smooth profile surface and for t/c<21%, with the proviso that r>96% of R. 
     
     
       16. The wind turbine according to  claim 14  and operable by pitch regulation and variable rotor speed, having at least one wind turbine blade longer than 30 meters, wherein the C L,d >1.4 for Re=3.0-11×10 6  corresponding to two-dimensional flow passing a smooth profile surface and for t/c<24%, with the proviso that r>96% of R. 
     
     
       17. The wind turbine according to  claim 16  wherein the C L,d >1.4 for Re=3.0-11×10 6  corresponding to two-dimensional flow passing a smooth profile surface and for t/c<21%, with the proviso that r>96% of R. 
     
     
       18. The wind turbine, according to  claim 1 , operable by pitch regulation and variable rotor speed, having at least one wind turbine blade longer than 30 meters, wherein the C L,d >1.3 for Re=3.0-11×10 6  corresponding to two-dimensional flow passing a smooth profile surface and for at least 90% of the blade in the range between blade radius r=30% of R to r=90% of R. 
     
     
       19. The wind turbine according to  claim 18 , wherein the C L,d >1.3 for Re=3.0-11×10 6  corresponding to two-dimensional flow passing a smooth profile surface and for at least 90% of the blade in the range between blade radius r=50% of R to r=80% of R. 
     
     
       20. The wind turbine according to  claim 18  and operable by pitch regulation and variable rotor speed, having at least one wind turbine blade longer than 30 meters, wherein the C L,d >1.4 for Re=3.0-11×10 6  corresponding to two-dimensional flow passing a smooth profile surface and for at least 90% of the blade in the range between blade radius r=30% of R to r=90% of R. 
     
     
       21. The wind turbine according to  claim 20 , wherein the C L,d >1.4 for Re=3.0-11×10 6  corresponding to two-dimensional flow passing a smooth profile surface and for at least 90% of the blade in the range between blade radius r=50% of R to r=80% of R. 
     
     
       22. The wind turbine according to  claim 1 , wherein said at least one wind turbine blade comprises carbon fibres. 
     
     
       23. The wind turbine according to  claim 22 , wherein the carbon fibres are main reinforcement fibres in at least one section of the wind turbine blade. 
     
     
       24. The wind turbine according to  claim 22 , wherein the carbon fibres are pultruded or belt pressed cured members. 
     
     
       25. A method of operation of a wind turbine according to  claim 1  under noise reduction condition comprising the steps of:
 adjusting the rotation speed to below nominal rotation speed, and 
 adjusting the pitch angle to minimise the decrease in annual yield. 
 
     
     
       26. The wind turbine according to  claim 1 , wherein
 the maximum lift coefficient, C L,max >1.4 for Re=1.5×10 6 , and/or 
 the maximum lift coefficient, C L,max >1.5 for Re=3.0×10 6 , and/or 
 the maximum lift coefficient, C L,max >1.6 for Re=5.0×10 6 , and/or 
 the maximum lift coefficient, C L,max >1.65 for Re=7.0×10 6 , and/or 
 the maximum lift coefficient, C L,max >1.68 for Re=9.0×10 6 , and/or 
 the maximum lift coefficient, C L,max >1.7 for Re=11.0×10 6 , 
 where C L,max  is valid for a two-dimensional flow passing a smooth profile surface, for at least 80 radius-% of the blade. 
 
     
     
       27. The wind turbine according to  claim 26 , wherein C L,max  is valid for a two-dimensional flow passing a smooth profile surface, for at least 90 radius-% of the blade. 
     
     
       28. The wind turbine according to  claim 1 , where the combined radius specific solidity is below a linear interpolation between:
 Sol r =0.035 at blade radius r=30% of the rotor radius R 
 Sol r =0.025 at blade radius r=50% of the rotor radius R 
 Sol r =0.018 at blade radius r=70% of the rotor radius R 
 Sol r =0.011 at blade radius r=90% of the rotor radius R, 
 for at least 75 radius-% of the blade(s) between blade radius r=30-90% of the rotor radius R. 
 
     
     
       29. The wind turbine according to  claim 1 , where the combined radius specific solidity is below a linear interpolation between:
 Sol r =0.035 at blade radius r=30% of the rotor radius R 
 Sol r =0.025 at blade radius r=50% of the rotor radius R 
 Sol r =0.018 at blade radius r=70% of the rotor radius R 
 Sol r =0.011 at blade radius r=90% of the rotor radius R, 
 for at least 95 radius-% of the blade(s) between blade radius r=30-90% of the rotor radius R.

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